Diabetes Mellitus : Information

Introduction : Diabetes Mellitus

Diabetes mellitus is a group of metabolic diseases in which the person has high blood glucose (blood sugar) level either due to inadequate insulin production or because the body's cells do not respond properly to insulin or both. The term "Diabetes Mellitus" describes a metabolic disorder of multiple etiology characterized by chronic hyperglycemia with disturbances of carbohydrate, fat (dyslipidaemia) and protein metabolism resulting from defects in insulin secretion, insulin action, or both. The main symptoms are: -

Polyuria (frequent urination) Polydipsia (increased thirst) Polyphagia (increased hunger

The main types of diabetes are:

Type 1 diabetes: It is due to the body's malfunction to produce insulin in the body, and requires the person to inject insulin. This form was previously referred to as "Insulin-Dependent Diabetes Mellitus" (IDDM) or "Juvenile Diabetes".

Type 2 diabetes: It is due to insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency. This form was previously referred to as non insulin-dependent diabetes mellitus (NIDDM) or "adult-onset diabetes". Type 2 diabetes can be prevented after following healthy life style such as healthy diet, proper exercise or maintaining healthy weight.

The third main form, Gestational diabetes occurs when pregnant women without a previous diagnosis of diabetes develop a high blood glucose level. It may lead to type 2 DM.

Other types of diabetes include those caused by:

  • Genetic defects of the beta cells, (the part of the pancreas that makes insulin) such as maturity-onset diabetes of the young (MODY) or neonatal diabetes mellitus (NDM)
  • Diseases of the pancreas or conditions that damage the pancreas, such as pancreatitis and cystic fibrosis
  • Excess amounts of certain hormones resulting from some medical conditions such as cortisol in Cushings syndrome that work against the action of insulin
  • Medications that reduce insulin action, such as glucocorticoids, or chemicals that destroy beta cells


Symptoms : Diabetes Mellitus

The main symptoms of diabetes are:

  • Polyuria: urinating frequently (particularly at night)
  • Polydipsia: feeling very thirsty
  • Polyphagia: feeling hungry frequently
  • Weakness
  • Weight loss and loss of muscle bulk
  • Frequent episodes of thrush
  • Cuts or wounds that heal slowly
  • Blurred vision

Type 1 diabetes can develop quickly, over weeks or even days. Many people have type 2 diabetes for years without realizing because early symptoms tend to be common.


Causes : Diabetes Mellitus

Type 1 Diabetes: The immune system of body attacks and destroys the cells that produce insulin. As no insulin is produced, glucose levels further increase, which can seriously damage the body's organs. Type 1 diabetes is often known as insulin-dependent diabetes. It is also sometimes known as juvenile diabetes or early-onset diabetes because it usually develops before the age of 40, often during the teenage years. Type 1 diabetes is less common than type 2 diabetes.

Type 2 Diabetes: Type 2 diabetes is where the body does not produce enough insulin or the body's cells do not respond to insulin. This is known as insulin resistance. Type 2 diabetes, and is far more common than type 1 diabetes.

Risk factors for type 2 diabetes:

  • Obesity or being overweight
  • Impaired glucose tolerance
  • High blood pressure
  • Dyslipidemia - Low levels of high-density lipoproteins (HDL) ("good") cholesterol and high levels of triglycerides, high low-density lipoproteins (LDL)
  • Gestational diabetes
  • Sedentary lifestyle
  • Family history
  • Age

Gestational Diabetes: Some women tend to experience high levels of blood glucose as during pregnancy due to reduced sensitivity of insulin receptors.


Diagnosis : Diabetes Mellitus

The clinical diagnosis of diabetics is often prompted by symptoms such as increased thirst and urination and recurrent infections.

Blood Tests - Fasting plasma glucose, two-hour postprandial test and oral glucose tolerance test are done to know blood glucose levels.

Glycated Haemoglobin (HbA1c) may be used to diagnose diabetes(if facilities are easily available).

Diabetes can be diagnosed by blood glucose and HBA1c levels:

Diabetes diagnostic criteria


2 hour* plasma glucose

Fasting plasma glucose






<7.8 (<140)

<6.1 (<110)


Impaired Fasting Glucose

<7.8 (<140)

6.1( 110) & <7.0(<126)

6.0 6.4

Impaired Glucose Tolerance

7.8 ( 140)

<7.0 (<126)

6.0 6.4

Diabetes mellitus

11.1 ( 200)

7.0 ( 126)


*Venous plasma glucose 2 hours after ingestion of 75g oral glucose load. Other tests
  • Fasting lipid profile, including total, LDL, and HDL cholesterol and triglycerides
  • Liver function tests
  • Kidney function tests
  • Thyroid stimulating hormone (TSH) in type 1 diabetes, dyslipidemia, or women over 50 years of age.
Reference: www.who.int
Management : Diabetes Mellitus

Currently, six classes of oral antidiabetic drugs (OADs) are available: biguanides (e.g., metformin), sulfonylureas (e.g., glimepiride), meglitinides (e.g., repaglinide), thiazolidinediones (e.g., pioglitazone), dipeptidyl peptidase IV inhibitors (e.g., sitagliptin), and -glucosidase inhibitors (e.g., acarbose).


  • Insulin: Type 1 diabetes is generally treated with combinations of regular and NPH (neutral protamine Hagedorn) insulin or synthetic insulin analogs. When insulin is used in type 2 diabetes, a long-acting formulation is usually added initially while continuing oral medications.
  • Treatment of coexisting medical conditions (high blood pressure, dyslipidemia etc.)
Lifestyle measures
  • Regular exercise
  • Proper diet
  • No smoking
  • No alcohol
These goals help in keeping both short-term and long-term blood glucose levels within acceptable limits.



Medical Condition : Diabetes Mellitus : Digestive